This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Have you ever been unable to bring to mind the full route to a recently visited restaurant, but nonetheless could recognize the correct turns as they came up along the way? This experience captures the distinction between two modes of memory retrieval. "Recall" is when you "bring to mind" things that are not currently present, such as when you remember all the turns you must take to get to your destination before setting out. By contrast "recognition" is when you can tell that something you currently experience is familiar, such as a given intersection where you must turn right, and is comparatively easier than recall. Many tests for nonhuman animals show that they can recognize something seen before as familiar, just as your dog or cat recognizes you when you come home. There is no doubt that animals have memory. But humans have different types of memory that depend on different parts of the brain, and we do not yet know whether monkeys or other animals share most of these different types of memory. We have discovered that rhesus monkeys can remember simple shapes and reproduce them later on a touchscreen computer, an ability that may show that they can "bring to mind" images that are physically absent, a powerful skill in humans. The development of this new technique for studying memory in monkeys will lead to more accurate characterization our cognitive evolution over the 30 million years that separate humans from our shared ancestor with rhesus monkeys. We have also documented factors that regulate memory for lists of stimuli, and have begun studies of memory for the source of information in monkeys. Studies of memory in monkeys will also help us understand what biological factors are responsible for the erosion of recall abilities that occurs in human amnesia and normal aging.